Kardar-Parisi-Zhang universality from soft gauge modes
Vir B. Bulchandani
Abstract
The emergence of superdiffusive spin dynamics in integrable classical and quantum magnets is well established by now, but there is no generally valid theoretical explanation for this phenomenon. A fundamental difficulty is that the hydrodynamic fluctuations of conserved quasiparticle modes are purely diffusive. We argue that in isotropic integrable magnets, a complete hydrodynamic description must include soft ``gauge'' degrees of freedom, that arise from spontaneous breaking of the Bethe pseudovacuum symmetry. We show that the coarse-grained time evolution of these modes lies in the Kardar-Parisi-Zhang universality class of dynamics.
Topics & Concepts
Integrable systemUniversality (dynamical systems)PhysicsQuantumQuasiparticleIsotropyRenormalization groupDegrees of freedom (physics and chemistry)Gauge theoryMathematical physicsQuantum mechanicsClassical mechanicsSuperconductivityQuantum many-body systemsPhysics of Superconductivity and MagnetismBlack Holes and Theoretical Physics